Labour has announced that the MP for Sheffield Hallam, Jared O’Mara, has been suspended from the party, after further revelations emerged about sexist remarks made on social media.

O’Mara, who unexpectedly unseated the former Liberal Democrat leader Nick Clegg in the 8 June election, apologised to his fellow Labour MPs on Monday night, telling them he had been on a “journey” since posting a series of offensive comments more than a decade ago.

But further claims have since emerged, including a foulmouthed confrontation with a woman in a Sheffield nightclub earlier this year – which O’Mara denies – and remarks in a music review unearthed by the Guido Fawkes website, which included the phrase “sexy little slags”.

A spokesman for Jeremy Corbyn, the Labour leader, said the decision had been taken because new information had come to light. “This kind of abusive, misogynistic, sexist language is completely unacceptable and will not be tolerated,” he said.

Temporary suspension from the party automatically implies that the Labour whip will be removed from O’Mara while the claims against him are investigated. He had already resigned from parliament’s women and equalities committee.

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Several high-profile Labour MPs had called for the suspension. Lucy Powell, the MP for Manchester Central and a former shadow education secretary, told ITV’s After the News programme: “One of the key questions you’re asked when you become a candidate for the Labour party, and you have to sign a contract to say this, is there anything in your past that would bring the party into disrepute?

“And I don’t understand, in all honesty, how Jared could have signed that paper. That’s why I think he should be suspended while that investigation is taking place.”

Lisa Nandy, another former shadow cabinet minister, also told an event on Tuesday that it was clear O’Mara should have been suspended.

The woman who alleges that she was verbally abused by O’Mara said the incident was witnessed by her friends. She told BBC2’s Daily Politics show she had first encountered O’Mara on a dating app, and while an initial meeting “didn’t really work out” there were no hard feelings.

She said, however, that O’Mara had later abused her – before he became an MP – when she encountered him while out with friends. Asked what O’Mara said, she replied: “Obviously, some of the things aren’t broadcastable. There were some transphobic slurs in there. He called me an ugly bitch.”

Speaking about these claims, a spokesman for O’Mara said: “He categorically denies the latest allegations.”

Corbyn was under pressure to take action before Wednesday’s prime minister’s questions, to avoid giving the Conservatives ammunition.

Theresa May was asked about O’Mara’s case by the former minister Nicky Morgan, who said: “What leadership and encouragement to the woman and girls in his constituency to take part in public life the member for Sheffield Hallam has shown in his remarks?”

May replied she wanted the House of Commons to be a place that young women aspire to come to. “All of us in this house should have due care and attention to the way in which we refer to other people, and should show women in public life the respect that they deserve,” she said.

O’Mara, who has cerebral palsy, has been a disability rights campaigner. The 35-year-old was adopted as a candidate in the two-week scramble to fill constituencies after the prime minister unexpectedly announced a snap general election in April.

A source close to Labour’s national executive committee said O’Mara’s selection in Sheffield had been backed by the local Momentum group, after the 2015 candidate Oliver Coppard did not stand again.

Tweets from the Momentum Sheffield account from the election campaign call on volunteers to campaign for O’Mara, calling him “the pro-Corbyn candidate”.

“There was a real problem in vetting all of those candidates so quickly after a snap election was called, it’s impossible to check almost 3,000 people in a week, apart from their party records, their criminal records and social media,” the source said. “These comments go back on fansites and sports sites from more than a decade ago.”

A Momentum source said local members had expressed concerns before O’Mara’s selection and denied he was explicitly backed by the group. “Though the local group obviously campaigned for him during the election, as every Momentum group did for their MP, he wasn’t most people’s first choice candidate and there were many reservations,” the source said.

“Unfortunately local members had little choice in backing him, as Jared was imposed by the NEC rather than being selected by local Labour party members.”